F-box only protein 32, also known as "MAFbx", for "Muscle Atrophy F-box gene", and "Atrogin-1," is a protein that in humans is encoded by the FBXO32gene.[5][6][7]
Function
This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of the ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbxs class and contains an F-box domain. This protein is highly expressed during muscle atrophy, whereas mice deficient in this gene were found to be resistant to atrophy. This protein is thus a potential drug target for the treatment of muscle atrophy. Alternative splicing of this gene results in two transcript variants encoding two isoforms of different sizes.[7]
FBXO32 gene has been observed progressively downregulated in Human papillomavirus-positive neoplastic keratinocytes derived from uterine cervical preneoplastic lesions at different levels of malignancy.[9] For this reason, FBXO32 is likely to be associated with tumorigenesis and may be a potential prognostic marker for uterine cervical preneoplastic lesions progression.[9]
de Palma L, Marinelli M, Pavan M, Orazi A (2008). "Ubiquitin ligases MuRF1 and MAFbx in human skeletal muscle atrophy". Joint Bone Spine. 75 (1): 53–7. doi:10.1016/j.jbspin.2007.04.019. PMID17977773.
Mascher H, Tannerstedt J, Brink-Elfegoun T, Ekblom B, Gustafsson T, Blomstrand E (2008). "Repeated resistance exercise training induces different changes in mRNA expression of MAFbx and MuRF-1 in human skeletal muscle". Am. J. Physiol. Endocrinol. Metab. 294 (1): E43-51. doi:10.1152/ajpendo.00504.2007. hdl:10616/40320. PMID17971512.
Petersen AM, Magkos F, Atherton P, Selby A, Smith K, Rennie MJ, Pedersen BK, Mittendorfer B (2007). "Smoking impairs muscle protein synthesis and increases the expression of myostatin and MAFbx in muscle". Am. J. Physiol. Endocrinol. Metab. 293 (3): E843-8. doi:10.1152/ajpendo.00301.2007. PMID17609255. S2CID2608857.
Kostek MC, Chen YW, Cuthbertson DJ, Shi R, Fedele MJ, Esser KA, Rennie MJ (2007). "Gene expression responses over 24 h to lengthening and shortening contractions in human muscle: major changes in CSRP3, MUSTN1, SIX1, and FBXO32". Physiol. Genomics. 31 (1): 42–52. doi:10.1152/physiolgenomics.00151.2006. PMID17519359.
Doucet M, Russell AP, Léger B, Debigaré R, Joanisse DR, Caron MA, LeBlanc P, Maltais F (2007). "Muscle atrophy and hypertrophy signaling in patients with chronic obstructive pulmonary disease". Am. J. Respir. Crit. Care Med. 176 (3): 261–9. doi:10.1164/rccm.200605-704OC. PMID17478621.
Ogawa T, Furochi H, Mameoka M, Hirasaka K, Onishi Y, Suzue N, Oarada M, Akamatsu M, Akima H, Fukunaga T, Kishi K, Yasui N, Ishidoh K, Fukuoka H, Nikawa T (2006). "Ubiquitin ligase gene expression in healthy volunteers with 20-day bedrest". Muscle Nerve. 34 (4): 463–9. doi:10.1002/mus.20611. PMID16868939. S2CID26515566.
Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, Berriz GF, Gibbons FD, Dreze M, Ayivi-Guedehoussou N, Klitgord N, Simon C, Boxem M, Milstein S, Rosenberg J, Goldberg DS, Zhang LV, Wong SL, Franklin G, Li S, Albala JS, Lim J, Fraughton C, Llamosas E, Cevik S, Bex C, Lamesch P, Sikorski RS, Vandenhaute J, Zoghbi HY, Smolyar A, Bosak S, Sequerra R, Doucette-Stamm L, Cusick ME, Hill DE, Roth FP, Vidal M (2005). "Towards a proteome-scale map of the human protein-protein interaction network". Nature. 437 (7062): 1173–8. Bibcode:2005Natur.437.1173R. doi:10.1038/nature04209. PMID16189514. S2CID4427026.
